Mark Hope
Hero
I've used them quite a few times, but wouldn't describe them as common. Every one of my campaigns has had a beholder or two in it here or there. I've used the ones that appear in Skullport, Wildspace, Curse of the Azure Bonds, of course. I had a iconic Elder Orb NPC in Undermountain that guarded a hall of portals that I devised up on level 1. It harrassed the PCs for several sessions until it was finally disintegrated by my sister's 20th level magic-user. I had a hive mother (caled Iris) that was not particularly malevolent and acted as a sort of seer. I placed a whole hive of the things in the Greyhawk Ruins adventure and dropped another one or two here or there over the years. Properly placed and used intelligently, they make for great opponents, especially of the long-term variety. I'm hoping to use the Eye of... series on my current group at some point, so that will be a laugh. Well, for me at least...